Generally, the intro-play operation of a digital audio disc player refers to a function that sequentially reproduces the forepart of a music item recorded on a disc for a certain period of time, for example, ten seconds. This period allows the listener to recall the contents of the entire music item. In the conventional method, the intro-play function enables the selection of the music item after listening to a portion thereof. Here, the function of selecting the desired music item and the function of storing the selected music item numbers are separate from each other.
FIG. 1 is a block diagram showing the structure of a conventional digital audio disk player. Referring to FIG. 1, a disc player consists of an input device 10, a microprocessor 20, a memory 30, a display 40 and a disc reproduction device 50. Input device 10 comprises a number of keys producing respective signals for selection of various functions to be executed by the disc player. For example, an intro-key K1 provides an intro-key signal for initiating an intro-play function, a play key K2 provides a play key signal for starting full reproduction, and a keypad K3 produces numerical signals corresponding to music item numbers for selecting music items are included in input device 10.
Microprocessor 20 controls a memory 30, a display 40, and a disc reproduction device 50 in order to perform the functions requested by a user according to the respective key-input signal provided by input device 10. That is, microprocessor 20 stores the desired music item number in memory 30, controls the reproduction sequence according to the music item number stored in memory 30, and then manipulates the information to be displayed on display 40. Disc reproduction device 50 extracts (via an optical pickup) and demodulates the table of contents (TOC) information recorded on the lead-in region of the disc (for example, a compact disc), audio data recorded in the music region, and data in the lead-out region. Then, the demodulated audio signal is converted into an analog signal to be processed through audio circuitry (i.e., equalizers, amplifiers, speakers etc.), while the sub-code data is stored in memory 30.
Microprocessor 20 carries out its various functions by referring to the sub-code data. Thus, the conventional disc player is unable to store the music item number during an intro-play operation since the intro-play and storing operations are separate from each other. Accordingly, the user must remember the desired music item numbers identified during intro-play and, when the intro-play operation is completed, the relevant music item numbers are successively stored in memory 30 by means of keypad K3 of input device 10. Only then can the stored music item numbers permit reproduction of the corresponding music items.
FIG. 2 is a flowchart showing steps for carrying out an intro-play function using the device of FIG. 1. Referring to FIG. 2, in step S1, while listening to a prerecorded disc, the user pushes intro-key K1 of input device 10 in order to select, for example, a music item. The disc player starts the intro-play function in step S2 according to the intro-key signal of input device 10. In step S3, microprocessor 20 indicates an intro-play function on display 40 and reads the TOC information recorded on the disc by controlling disc reproduction device 50. This TOC information is then stored in memory 30. A pointer for a recorded music item, the music item's starting time (hour, minutes & seconds), and an index are recorded in the TOC. In addition to this, microprocessor 20 initializes the music item number (i) to "01" in order to sequentially reproduce the music items starting from the first one. Therefore, the intro-play operation starts from music item number 01. In general, the music item number (i) is available from 01 to 99. Here, however, since the number of music items recorded on a given disc varies from disc to disc, the last music item number (i.sub.LAST) can be sought by referring to the TOC.
In step S4, disc reproduction device 50 starts reproduction of the music item selected according to the music item number (i), under control of microprocessor 20, and counts the reproduction time (t). In step S5, the reproduction time (t)is continually compared with a predetermined reference time, so that each music item can be reproduced for a specific duration in step S4. That is, the intro-play operation does not reproduce the entire music item but reproduces only the forepart of the music item corresponding to the predetermined reference time, in order to quickly reveal the contents of a recorded music item and thereby enable the user to make a music item selection. For example, if the reference time is fixed as ten seconds, the reproduction time after the start time of step S4 is examined. When ten seconds have elapsed in step S5, the program advances to step S6, wherein the next music item can be reproduced by incrementing the music item number (i) by 1. In step S7, it is determined whether an intro-play operation of the final recorded music item has been completed, by comparing the music item number (i) with the last music item number (i.sub.LAST). That is, if (i) is less than (i.sub.LAST), then the next music item is reproduced in step S4.
FIG. 3 is a flowchart showing steps for carrying out a music memory function using the device of FIG. 1. Referring to FIG. 3, it is important to note that the user must remember the desired music item number during the intro-play operation. When the intro-play operation is finished, the user inputs the appropriate music item number or numbers. That is, during step S8, the user inputs the desired music item numbers to microprocessor 20 by pushing (entering) the proper keys of keypad K3 of input device 10. In step S9, microprocessor 20 then stores the input music item numbers in a specific region of memory 30, in input order.
FIG. 4 is a flowchart showing steps for carrying out the play function using the device of FIG. 1. Referring to FIG. 4, in step S10, play key K2 of input device 10 is pushed and the play key signal is input to microprocessor 20 so as to play the music items corresponding to the stored music item numbers stored in memory 30. Then, in step S11, reproduction starts in accordance with the input of the play key signal. During step S12, microprocessor 20 sequentially reproduces the music items corresponding to the music item numbers stored in memory 30, by controlling disc reproduction device 50 to thereby enable listening.
As described above, conventional disc player operation includes steps for intro-playing the music item, storing the desired music item number, and reproducing the selected music item. Accordingly, the user is inconvenienced by the need to remember the desired music item numbers during the intro-play operation. This problem is exacerbated when many potential music items exist.